Re: Return of PENDING status to SCSI driver

[Boaz Harrosh <bharrosh-C4P08NqkoRlBDgjK7y7TUQ@public.gmane.org>]

On 06/15/2009 05:07 PM, Ramya Desai wrote:
> On 6/15/09, Alan Stern <stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org> wrote:
>> On Mon, 15 Jun 2009, Boaz Harrosh wrote:
>>
>>  > >> If you are using the existing USB mass storage infrastructure then
>>  > >>  it will not work. This is because all commands are issued from a
>>  > >>  thread per host, which does a synchronous execution of one command
>>  > >>  at a time. In fact it does not even have a Q, but a global one cmnd
>>  > >>  pointer per host. And therefor sets can_queue to 1.
>>  > >>
>>  > >>  Are you using the existing USB infrastructure?
>>  > >>
>>  > >>
>>  > >>  Boaz
>>  > >>
>>  > > I am replacing the default USB mass storage driver with the one I am
>>  > > developing. But I am using the default SCSI and USB stack provided by
>>  > > Linux.
>>  > >
>>  > > So is there any another way to make my driver asynchronous?
>>  > >
>>  > > -RD
>>  >
>>  > I was afraid so.
>>  >
>>  > There is a lot of code you will need to change in current USB storage stack
>>  > SCSI is built with native support for queuing, but not so USB-storage-stack.
>>
>>
>> Boaz:
>>
>>  It looks like you didn't read Ramya's reply to your last message.
>>  Ramya isn't keeping the USB storage "stack" -- it is being replaced by
>>  a new driver -- so there's no point talking about making changes to it.
>>
>>
>>  Alan Stern
>>
>>
> 
> I already have an array length of 10 for the bellow members.
>        struct scsi_cmnd        *srb;            /* current srb         */
>        unsigned int            tag;              /* current dCBWTag     */
> 

That's good

> I am maintaining an internal queue for the commands.
> My main problem is , I am not getting the next command in my USB
> storage driver ( My custom) , until the first command is done.
> How can I get the next command, while processing the first command?
> 
> -Ramya

Post the code you have missed something, I'll have a look
Boaz
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